>> reporter: casey anthony was crying for much of the day. more very hard to watch photos of her daughter's skull were shown in the courtroom. she stopped crying and got angry, angry because of what a medical examiner said, a medical examiner declaring today this death was a homicide. now, it's very important for casey anthony and her attorneys to get the jury to believe there was no homicide of her daughter. casey anthony saying her daughter drowned accidentally and she was so panicked by it she decided that she would spend the rest of her life not telling anybody her daughter drowned. that is what the defense is telling this jury. what the medical examiner said in her career as a medical examiner, in 100% of the accidental drowning cases here in orange county, florida, 0% of the parents did not report the drowning. that is one of the reasons she declared this to be a homicide. listen. >> when a child is not reported immediately to authorities, either with an injury, that's something we look for for foul play. this child, from history, was n